1. Field of the Invention
This invention relates to a light-sensitive recording material which basically comprises a non-silver light-sensitive compound, more particularly, to a light-sensitive composition for a light-sensitive recording material.
2. Description of the Prior Art
A large number of studies have hitherto been made on light-sensitive recording systems using chalcogen compounds which consisting mainly of one or more elements selected from sulfur, selenium and tellurium. For example, Japanese Patent Publication 6,142/72 discloses a recording system which uses a light-sensitive recording material having, as a basic constituent, laminated layers comprising a layer of a chalcogen compound and a layer of a metal and which forms a latent image capable of being developed and intensified by physical development after exposure to light through an image.
Moreover, there is known a method employing a semi-conductive sulfide such as lead sulfide and forming an image by etching which is effected by taking advantage of the difference in solubility in an electrolytic solution between exposed areas and unexposed areas, as described in Soviet Physics Semiconductors, Vol. 7, p. 136 (1973).
In addition, recording materials for holograms have been studied which take advantage of differences in the light absorption between irradiated areas and unirradiated areas that result from laser ray irradiation of a thin film of arsenic sulfide, as described in Applied Physics Letters, Vol. 19, p. 205 (1971).
In particular, many studies have been made on light-sensitive materials which make use of the photodoping phenomenon, i.e., materials which have, as a basic constituent, a layer of a chalcogen composition and a metallic layer and which form an image upon light irradiation, i.e., it is known that when a light-sensitive recording material comprising laminated layers composed of a chalcogen composition layer and a metallic layer are subjected to appropriate irradiation, a mutual diffusion (photodoping) is caused between both of the layers at irradiated areas to form a mutual diffusion product, thus yielding an image corresponding to the light irradiation pattern, as described in Soviet Physics Solid State, Vol. 8, p. 451 (1966), Japanese Patent Application Laid-Open 5,324/74, U.S. Pat. Nos. 3,637,377 to 3,637,381 and 3,637,383.
The above light-sensitive recording materials have been used for the preparation of photomasks for integrated circuit manufacture, printed circuit board manufacture and the like, since the images obtained generally have excellent resolution (high resolving power) and transmit some visible rays, so that registration is easily done. Moreover, it has been proposed to use these materials for slides, as light-sensitive materials for microphotography, as light-sensitive materials for holograms and other uses.
In addition, it is possible to clarify an image formed by the above process by selectively attaching a printing ink to the above light-sensitive recording material by taking advantage of the difference in wettability between exposed areas and unexposed areas on the surface thereof. It is also possible to transfer the attached printing ink to a paper and the like. Therefore, such light-sensitive recording materials can also be used as printing plates. Furthermore, the application of light-sensitive recording materials which make use of photodoping in a wide range is probable since development is unnecessary, fixing is not necessarily required, they can be handled in the light, and have excellent resolution.
Chalcogen compositions comprising light-sensitive recording materials of the prior art as described above mainly comprise a chalcogen glass containing arsenic as a primary component. That is, most of them are mainly composed of an arsenic-sulfur series glass, an arsenic-selenium series glass or an arsenic-sulfur-tellurium series glass. Light-sensitive materials using such chalcogen glasses are disadvantageous in that their photosensitivity is low, and therefore, long-time exposure is required in order to obtain a clear image using a high-pressure mercury lamp. Moreover, they have another disadvantage in that their toxicity is considerable because of the presence of arsenic as a main component, which hinders their practical use.
Recently, studies to eliminate the aforesaid defects have been made. For example, the use of a chalcogen glass comprising germanium-sulfur has been proposed, as described in Japanese Patent Application Laid-Open 71,626/73. This series is quite different in the absence of arsenic from the chalcogen glasses described hereinbefore.
However, according to research by the present inventors, it has been found that while light-sensitive recording materials using a germanium-sulfur series glass are excellent in showing no toxicity, they suffer the disadvantage that sensitivity is relatively low, and therefore, long-time exposure is required, making their practical use difficult.